Abstract: The tree-processing unit includes a tubular member detachably secured to the boom support of a conventional motorized equipment, an elongated boom extending through both ends of the tubular member, guide means located within the tubular member for guiding and supporting the boom through the tubular member, and hydraulically-operated means mounted on the tubular member and on the front end of the boom for gripping and delimbing a felled tree. The hydraulic lines interconnecting the hydraulically-operated means located at the front end of the boom and the tubular member, are maintained in a tight condition all the time to prevent tangling of the lines with the equipment and other obstacles on the working site. A guide mechanism located within the tubular member includes a plurality of roller bogeys.